Multi-pin integrated chips, oftentimes referred to as a pin grid array (or dual in-line package or single in-line package), are typically mounted on a circuit board in a removable manner. In this way, the IC package can be removed and replaced as desired. In the past, this removable mounting of the IC package has been achieved through use of a socket adapter. The socket adapter includes a plurality of socket terminals which have ends that fit into holes in the circuit board to achieve a connection with electrical contacts on the circuit board. The terminal sockets are also adapted to removably receive the pins on the IC package to thereby result in an electrical connection between the circuitry on the integrated chip and the electrical contacts on the circuit board.
These types of adapters have gained some amount of acceptance in the industry as they provide a useful way of mounting integrated chips on a circuit board in a removable manner. However, these adapters are somewhat limiting in that with the through-hole components, only one side of the circuit board can be used for components. This, of course, means that up to fifty percent of the potential surface area on the circuit board is unavailable for use.
Socket adapters which employ through-hole technology have also been used in conjunction with printed circuit boards that incorporate surface mount components as a way of attempting to more fully utilize the available surface area of the printed circuit board. However, this alternative requires dual manufacturing methods--namely wave soldering to connect the through-hole components and solder reflow or hand soldering to connect the surface mount components.
Surface mount type socket adapters which are used for connecting IC packages to surface mount components on the circuit board are useful in that they allow both sides of the printed circuit board to be used. In these types of socket adapters, signals are carried via a circuit from the pins on the IC package to J type or gull wing leads attached to the edges of the socket adapter which are soldered to pads on the printed circuit board.
This surface mount type of adapter is typically much larger than the mating IC package since all of the signal lines must be distributed to the edges. Also, these adapters are typically a solid structure which raises concerns about the planarity of the adapter during the process of soldering the J type or gull wing lead connections. These adapters are also typically not designed to provide adequate air flow between the pin interstices to achieve efficient cooling and so concerns arise about heat dissipation and the potentially adverse effects of thermal expansion. Further, adapters of this type are not well suited for use with many IC packages having a high pin count because the solder joints of the interior pins are not readily accessible for inspection and rework.
As a general matter, many types of adapters are also not well suited for preventing electrical interference or crosstalk between adjacent signal connections. As the signal speed becomes higher and the signal connections located closer to one another, this interference or crosstalk becomes even more problematic. This concern with electrical interference or crosstalk also arises in other contexts such as, for example, when one printed circuit board (e.g., a daughter board) is mounted on another printed circuit board (e.g., a mother board) and in the case of fast clock speed or high speed data transition.
In view of the foregoing, it would be highly desirable to provide an adapter for a multi-pin component such as an IC package which addresses the foregoing concerns. In particular, it would be desirable to provide an adapter which, when used in connection with circuit boards having surface mount components, allows the solder joints to be inspected and, if necessary, reworked. Providing an adapter which allows significant air flow between the pin interstices and which is adapted to be used in conjunction with IC packages having a wide variety of pin arrangements would also be desirable. It would also be useful to provide an adapter that is well suited for preventing crosstalk or interference between adjacent signal connections.